Pyridinium

RoCo® is a leading manufacturer and supplier of ionic liquids and chemical precursors in North America, offering products with purity levels exceeding 99% for applications in energy storage, catalysis, fuel desulfurization, water remediation, drug delivery, antimicrobial solutions, CO₂ separation, and material science.

Pyridinium Overview

Pyridinium-based ionic liquids (ILs) are aromatic, quaternary ammonium compounds with a planar, six-membered ring structure, valued for their thermal stability and electron-withdrawing properties. Unlike imidazolium-based ILs, pyridinium cations lack a protonation-prone C2 carbon, preventing carbene formation and enhancing electrochemical stability in battery applications. The distributed positive charge across the aromatic ring reduces side reactions, making them ideal for high-performance electrolytes. Their flat structure facilitates strong π-π interactions, enhancing interactions with aromatic compounds like dibenzothiophene (DBT) in fuel desulfurization. Pyridinium-based systems exhibit high aqueous solubility (up to 400% increase over precursors) and antimicrobial properties, enabling water remediation, biomedicine, and gas separation applications.

• Thermodynamic Properties

Chaban and Prezhdo investigated electronic polarization in pyridinium-based ILs ([PY][Cl], [PY][BF₄], [PY][N(CN)₂]) using DFT-based molecular dynamics from 300 to 900 K. Electron delocalization remains nearly constant, with cation charges stable (e.g., 0.52–0.54 e for [PY][Cl], 0.80–0.82 e for [PY][BF₄]), indicating robust noncovalent interactions. Dipole moments increase significantly with temperature due to thermal fluctuations, e.g., from 8.6 D (300 K) to 10.8 D (900 K) for [PY][Cl], and 12.5 D to 16.5 D for [PY][BF₄], enhancing dielectric properties. Pyridinium ILs are fragile liquids, exhibiting large viscosity and heat capacity changes near glass transitions (~180–181 K, similar to [bmim][Tf₂N]), with non-Arrhenius behavior. Their planar structure and electron-withdrawing nature suggest lower melting points than non-aromatic ILs.

Figure 1: A planar, six-membered aromatic ring (hexagon) with a circle inside, indicating aromaticity, or alternating double bonds. The nitrogen (N⁺) at position 1 bears a positive charge and is bonded to a butyl group (–CH₂–CH₂–CH₂–CH₃). The five carbon atoms (positions 2–6) are each bonded to a hydrogen atom. This flat structure highlights the electron-withdrawing nature and thermal stability of pyridinium. The hydrogen atoms are removed for the sake of simplicity.

Applications

Pyridinium-based ILs are utilized across industries:
• Electrochemistry: Serve as electrolytes in batteries and supercapacitors, leveraging high ionic conductivity, wide electrochemical windows, and stability from distributed charge.

• Catalysis: Enhance reaction efficiency and selectivity in organic synthesis, driven by electron-withdrawing properties.

• Fuel Desulfurization: Excel in oxidative-extractive desulfurization (OEDS), achieving 89.5% DBT removal from model fuels at 30 °C with [BPy][BF₄] (1:1 IL-to-fuel ratio, 4.0 vol% H₂O₂, 35 min), due to strong π-π interactions and hydrogen bonding.

• Water Remediation: Poly(ionic liquid) hydrogels with pyridinium units remove pollutants like sodium diclofenac (166.7 mg/g) and methyl orange (218.8 mg/g) from water, leveraging ionic interactions and high swelling (297% after 2 h).

• Drug Delivery: Pyridinium-based hydrogels release ~70% of loaded diclofenac within 24 h, controlled by polymer relaxation, ideal for controlled-release systems.

• Antimicrobial Applications: Exhibit antibacterial activity against E. coli (22 mm zone of inhibition) and S. aureus (23 mm), and antifungal activity against Candida albicans (15 mm), with low toxicity up to 100 μM.

• CO₂ Separation: Pyridinium-type poly(ionic liquids) blended with [C6mim][Tf₂N] achieve CO₂ permeability of 74.7 Barrer and CO₂/N₂ selectivity of 38.7 at 35 °C, ideal for gas separation membranes.

• Green Chemistry: Low volatility and recyclability (e.g., via distillation and re-extraction) support sustainable processes.

• Material Science: Stabilize nanoparticles and produce conductive polymers, leveraging planar structure.

• Electronics: High ionic conductivity, thermal stability, low volatility, and non-flammability make them ideal for cooling in energy storage and electronic devices.

RoCo® offers products like N-Butylpyridinium

Bis(trifluoromethylsulfonyl)amide ([BPy][Tf₂N]) (CAS NO: 187863-42-9) and N-Butylpyridinium Tetrafluoroborate ([BPy][BF₄]) (CAS NO: 203389-27-9). These features include high solubility, low viscosity, and excellent conductivity, tailored for diverse industrial needs.

Why RoCo®?

With decades of expertise, RoCo® delivers high-purity pyridinium-based ILs for research and industry. Custom synthesis ensures ultra-high purity (>99.9%), meeting stringent standards. Competitive pricing and expert support drive success from lab to production, supporting applications in electrochemistry, catalysis, desulfurization, water remediation, drug delivery, antimicrobial solutions, CO₂ separation, green chemistry, and material science.

Partnership with IoLiTec

As a North American distributor for IoLiTec Ionic Liquids Technologies GmbH, RoCo® combines its synthesis expertise with IoLiTec’s premium products, offering comprehensive solutions for next-generation batteries, fuel processing, environmental technologies, biomedical applications, and sustainable processes.

Drive Innovation with RoCo®

RoCo® fuels innovation with high-purity pyridinium-based ILs (≥99%) and custom synthesis for ultra-high purity (≥99.9%). Our IoLiTec partnership ensures consistent performance. With competitive pricing, technical expertise, and a sustainability focus, RoCo® meets the needs of researchers and industries. Explore our products and contact us today!